Name:	fsm_DebtInstrumentAverageTradingPricePercentageOfAverageConversionValueOfNote
Namespace Prefix:	fsm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Amount of convertible debt portion allocated to equity.

No definition available.

Name:	fsm_DebtInstrumentsConvertibleEquityComponent
Namespace Prefix:	fsm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The price per share of the conversion feature embedded in the debt instrument.

No definition available.

Name:	fsm_IfrsDebtInstrumentConvertibleConversionPrice
Namespace Prefix:	fsm_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

No definition available.

Name:	fsm_IfrsDebtInstrumentConvertibleConversionRatio
Namespace Prefix:	fsm_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

Percentage of principal amount of debt redeemed.

No definition available.

Name:	fsm_IfrsDebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed
Namespace Prefix:	fsm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Proceeds from convertible debenture.

No definition available.

Name:	fsm_ProceedsFromConvertibleDebenture
Namespace Prefix:	fsm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The interest rate on borrowings. [Refer: Borrowings]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 7
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_7&doctype=Standard
-URIDate 2020-01-01

Name:	ifrs-full_BorrowingsInterestRate
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The amount of deferred tax related to items credited (charged) directly to equity. [Refer: Deferred tax expense (income)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 12
-IssueDate 2020-01-01
-Paragraph 81
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2020-en-r&anchor=para_81_a&doctype=Standard
-URIDate 2020-01-01

Name:	ifrs-full_DeferredTaxRelatingToItemsChargedOrCreditedDirectlyToEquity
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

No definition available.

Name:	ifrs-full_DisclosureOfDetailedInformationAboutBorrowingsLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The cash outflow for interest paid, classified as financing activities.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2020-01-01
-Paragraph 31
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2020-en-r&anchor=para_31&doctype=Standard
-URIDate 2020-01-01

Name:	ifrs-full_InterestPaidClassifiedAsFinancingActivities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The nominal or face amount of a financial instrument, used to calculate payments made on that instrument.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2020-01-01